Heat sink

ABSTRACT

A heat sink includes an airflow generator, a first set of fins, and a ventilation unit separated from the first fin set. The ventilation unit further includes a second set of fins and two vents. The airflow generator generates airflow that flows through the first fins for removing heat from a primary heat source and is then guided toward and through the second fins for removing heat from a secondary heat source and eventually discharged through the vents.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates generally to a heat sink, and in particular to a heat sink that generates air flows in two or more direction with a single fan.

[0003] 2. The Prior Art

[0004] When a machine, especially an electronic device, such as a computer, is operated continuously, heat is inevitably generated to sometimes even damage the internal parts or shorten service life of the machine. A heat sink is often employed to remove the heat in order to maintain proper operation of the electronic device.

[0005] The heat sink may be classified into two categories of which the first one comprising a single fan and two vents as shown in FIG. 3 of the attached drawings. Disadvantages of the know heat sink are poor performance in removing heat for heat is conducted through a number of heat interface and/or heat pipes and being noisy in operation. The second category of the heat sink has fins of insufficient area and a single vent only (shown in FIG. 4) that cannot dissipate heat efficiently.

[0006] Therefore, it is desired to have a structure of the heat sink that eliminates the above defects.

SUMMARY OF THE INVENTION

[0007] A primary objective of the present invention is to provide a heat sink capable of guiding airflow to a first set of fins in contact with a primary heat source through a first airflow guiding device and meanwhile reducing noise. In addition, airflow is further guided to a secondary heat source through a second airflow guiding device for removing heat thereof.

[0008] In order to realize abovesaid objective, a heat sink of the present invention is comprised of a first airflow guiding device, a first set of fins, a second airflow guiding device, and a ventilation unit composed of a second set of fins and two vents, in which airflow is guided through the first airflow guiding device to the first fins located on a primary heat source for cooling the primary heat source, then guided through the second airflow guiding device arranged along the circumference of the first fins to reach the second fins located on a secondary heat source for cooling the secondary heat source, and finally discharged through the ventilation unit without inducing much noise.

[0009] For more detailed information regarding advantages or features of this invention, a preferred embodiment of the present invention will be described with reference to the annexed drawings.

BRIEF DESCRIPTION OF DRAWINGS

[0010] The related drawings in connection with the detailed description of the present invention to be made later are described briefly as follows, in which:

[0011]FIG. 1 is a schematic plan view of a heat sink constructed in accordance with the present invention with a combined cooling fan;

[0012]FIG. 2 is a schematic plan view showing heat sources from which heat is removed by the heat sink of the present invention;

[0013]FIG. 3 is a schematic plan view of a conventional heat sink;

[0014]FIG. 4 is a schematic plan view of another conventional heat sink; and

[0015]FIG. 5 is a schematic plan of a heat sink constructed in accordance with another embodiment of the present invention with a combined cooling fan.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0016] Wherever possible, the same reference numerals will be used throughout the drawings and the description for easy cross-reference to the same or like parts.

[0017] Referring to FIG. 1, a heat sink constructed in accordance with the present invention comprises a base 1, a first set of fins 2, an airflow generator 3, and first and second ventilation units 4, 5. On the base 1 surrounded partly by a side wall 11, there is a space for accommodating the airflow generator 3, which can be a fan for example. An airflow guiding device and the fins are arranged on the opposite open side.

[0018] The airflow guiding device comprises first and second airflow-guiding sets 12,13. The first airflow-guiding set 12 is radially spaced from and located nearby the fan 3 for guiding the airflow generated towards the first fin set 2. The second airflow-gliding set 13 is arranged along outer circumference of the first fin set 2 and towards the ventilation units 4, 5 that comprise second sets of fins 41A, 41B, 51A, 51B. The airflow travels through gaps of in the second fin sets and discharged through two vents 42, 52.

[0019]FIG. 2 is a schematic plan view of distribution of heat sources from which heat can be removed by the heat sink of this invention. As indicated in FIG. 2, the first fin set 2 is located on a primary heat source 2′ and the first and the second ventilation devices 4, 5 are located exactly above secondary heat sources 4′, 5′, respectively. By such an arrangement, airflow is guided through the first airflow-guiding set 12 towards the first fin set 2 for cooling the primary heat source, and then guided through the second airflow-guiding set 13 towards the second fin sets 41A, 41B above the secondary heat source 4′ and the second fin sets 51A, 51B above the secondary heat source 5′ to remove heat from the secondary heat sources 4′, 5′. Eventually, the air flow is discharged through the vents 42, 52.

[0020]FIG. 5 is a schematic plan view showing another embodiment of the present invention with a combined cooling fan. In FIG. 5, the first fin set 2 is split into two portions respectively directed towards the two vents to also serve as airflow-guiding means for guiding airflow to cool down those secondary heat sources. This simplifies the structure of the heat sink.

[0021] From above described, it is understood that the present invention is capable of cooling primary and secondary heat sources and reducing noise through airflow-guiding sets by using only a single cooling fan.

[0022] Although the preferred embodiments have been described in detail with reference to the drawings annexed, it is apparent that numerous changes or modifications may be made without departing from the true spirit and scope thereof, as set forth in the claims below. 

What is claimed is:
 1. A heat sink comprising an airflow generator, a first fin set, and a ventilation set separated from the first fin set, the ventilation set further comprising a second fin set and a plurality of vents, wherein airflow generated by the airflow generator flows through the first fin set and is further guide toward the second fin set for respectively removing heat therefrom.
 2. The heat sink according to claim 1, wherein the airflow generator is a fan.
 3. The heat sink according to claim 1, wherein the first and second fin sets are arranged for respectively contacting a primary heat source and a secondary heat source.
 4. The heat sink according to claim 1, wherein an airflow-guiding set is arranged between the airflow generator and the first fin set.
 5. The heat sink according to claim 1, wherein an airflow-guiding set is arranged between the first fin set and the second fin set. 